1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "gc/heap.h"
18 #include "gc/space/large_object_space.h"
19 #include "gc/space/space.h"
20 #include "sticky_mark_sweep.h"
21 #include "thread-inl.h"
22 
23 namespace art {
24 namespace gc {
25 namespace collector {
26 
StickyMarkSweep(Heap * heap,bool is_concurrent,const std::string & name_prefix)27 StickyMarkSweep::StickyMarkSweep(Heap* heap, bool is_concurrent, const std::string& name_prefix)
28     : PartialMarkSweep(heap, is_concurrent,
29                        name_prefix.empty() ? "sticky " : name_prefix) {
30   cumulative_timings_.SetName(GetName());
31 }
32 
BindBitmaps()33 void StickyMarkSweep::BindBitmaps() {
34   PartialMarkSweep::BindBitmaps();
35 
36   WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
37   // For sticky GC, we want to bind the bitmaps of all spaces as the allocation stack lets us
38   // know what was allocated since the last GC. A side-effect of binding the allocation space mark
39   // and live bitmap is that marking the objects will place them in the live bitmap.
40   for (const auto& space : GetHeap()->GetContinuousSpaces()) {
41     if (space->IsContinuousMemMapAllocSpace() &&
42         space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect) {
43       DCHECK(space->IsContinuousMemMapAllocSpace());
44       space->AsContinuousMemMapAllocSpace()->BindLiveToMarkBitmap();
45     }
46   }
47   GetHeap()->GetLargeObjectsSpace()->CopyLiveToMarked();
48 }
49 
MarkReachableObjects()50 void StickyMarkSweep::MarkReachableObjects() {
51   // All reachable objects must be referenced by a root or a dirty card, so we can clear the mark
52   // stack here since all objects in the mark stack will Get scanned by the card scanning anyways.
53   // TODO: Not put these objects in the mark stack in the first place.
54   mark_stack_->Reset();
55   RecursiveMarkDirtyObjects(false, accounting::CardTable::kCardDirty - 1);
56 }
57 
Sweep(bool swap_bitmaps)58 void StickyMarkSweep::Sweep(bool swap_bitmaps) {
59   SweepArray(GetHeap()->GetLiveStack(), false);
60 }
61 
62 }  // namespace collector
63 }  // namespace gc
64 }  // namespace art
65